Diagnostic assays for detecting or measuring analytes often require at least partial purification of the analyte. One method commonly used in analytical assays such as immunoassays or nucleic acid testing involves binding of the analyte either directly or indirectly to a particle. Thus, particles capable of either directly or indirectly binding the analyte have to be provided to the sample to be tested. Particles may be provided in a solid form, but preferably are provided as a suspension of particles in a solution, generally by transferring an aliquot of the solution comprising the suspended particles using a pipetting device.
When such analyte-binding particles are provided as a suspension in a solution, care has to be taken that the suspension is homogenous when an aliquot is aspirated by the pipetting device for transfer to the sample. Commonly, containers comprising a solution of such suspended particles are subjected to shaking of the container using a shaking mechanism. The homogeneity of the suspended particle solution may be affected by the shaking movement itself carried out by the shaking mechanism and by the design of the container.